Cam switch unit

ABSTRACT

A cam switch unit that can be used singly or in multiples operated by a common actuating means. Each cam switch unit comprises an operating cam mounted centrally in a casing, and a pair of switch housing cavities, one on each side of the operating cam. The cavities each contain a fixed contactor and a movable contactor operated by the cam. Each cavity is closed by a cover, and each switch unit further comprises an upright cylindrical portion on the top of the casing and a cavity in the bottom of each casing for receiving the upright cylindrical portion of an adjacent unit to align and interlock adjacent units in a multiple switch assembly. Adjacent units are attached together by screw means having an externally threaded stem and a head having an externally threaded cavity for receiving the stem of an adjacent unit. These screw means also attach the switch cavity covers to the switch casing on each individual unit.

llnite its [72] Inventor Teizo lFujita 3-34, Nalta, Tezultayama,Sumiyoshi-ltu, Osaka, Japan [21] Applv No. 840,982 [22] Filed July11,1969 [45] Patented Oct. 19, 19711 [32] Priority Nov. 18, 1968 [33]Japan [31 1 43/84.,281)

[54] CAM SWITCH (NWT 5 Claims, 7 Drawing Figs. [52] US. Cl ZOO/168 A,200/ 168 K [51] Int. Cl H0111 9/02 [50] Field of Search 200/6, 14, 153,13, 1688, 168A, 16613,]67, 166.1

[56] References Cited UNl'TED STATES PATENTS 2,626,334 l/1953 KoenigZOO/6 UX 3,251,956 5/1966 Rasor et al 3,315,060 4/1967 Rothweileret al200/167 A 3,359,392 12/1967 Heath 200/6 X 3,493,696 2/1970 Rothweiler200/166 l X Primary Examiner-H. 0. Jones Atl0rney-Birch, Swindler, McKie-& Beckett ABSTRACT: A cam switch unit that can be used singly or inmultiples operated by a common actuating means, Each cam switch unitcomprises an operating cam mounted centrally in a casing, and a pair ofswitch housing cavities, one on each side of the operating cam. Thecavities: each contain a fixed contactor and a movable contactoroperated by the cam. Each cavity is closed by a cover, and each switchunit further comprises an upright cylindrical portion on the top of thecasing and a cavity in the bottom of each casing for receiving theupright cylindrical portion of an adjacent unit to align and interlockadjacent units in a multiple switch assembly. Adjacent units areattached together by screw means having an externally threaded stem anda head having an externally threaded cavity for receiving the stem of anadjacent unit. These screw means also attach the switch cavity covers tothe switch casing on each individual unit.

PMENIEDUU 19 IHYI SHEET 2 [IF 2 FIG.

CAM svvrrcri UNII'II The present invention relates to a cam switch unitused for switching an operation.

The present invention has for its object the provision of a cam switchunit of the type which comprises a casing, an operating cam mountedcentrally in said casing, a movable member received in each of cavitiesformed in said casing on both sides of said operating cam, a movablecontactor carried by said movable member and a fixed contactor disposedin each of said cavities for cooperation with said movable contactor,characterized in that each of said cavities is closed by a cover withsaid respective members disposed therein.

According to the present invention, control, assembly, maintenance andinspection of the unit switch can be effected easily.

FIG. 1 is a front elevation of a cam switch assembly composed of aplurality of unit cam switches arranged in juxtaposed relation;

FIG. 2 is a perspective view of a unit cam switch;

FIG. 3 is a perspective view of the unit cam switch with a cover of oneof switching members accommodating cavities removed;

FIG. 4 is a perspective view of the unit cam switch showing theswitching members in one of the cavities in an exploded state;

FIG. 5 is a top plan view of the unit cam switch, with an operating cammounted, showing the relative positions of said operation cam and theswitching members; and

FIGS. 6 and 7 are side elevations ofthe unit cam switch with a portionthereof shown in section respectively.

A preferred embodiment of the present invention will be described indetail hereinafter with reference to the accompanying drawings:

An elongate box-shaped switch casing ll, molded of a suitable material,is formed with a stepped hole 3 in the center thereof for mounting anoperating cam 2, and with cavities 4 in the longitudinally opposed endportions on both sides of said stepped hole 3. In each cavity 4 ismounted a fixed contactor 5 with a connecting terminal end 5a extendingoutwardly through the casing. A movable member 6 made of an insulatingmaterial has a through-hole 6a formed therein, through which a movablecontactor 7 and a stopper plate 8 extends with the former located closerto an end 619 of said movable member, which end is to be operated by theoperating cam, and with the latter located closer to the other end 60 ofsaid movable member, which end is to indicate the operational positionof the cam switch, said movable contactor and said stopper plate 8 beingsecured in said through-hole 6a by means of a spring 9 interposedtherebetween. A channel it) is formed extending from the outside surfaceof the casing I to the central stepped hole 3 across the cavity 4 toprovide for a reciprocal sliding movement of the movable member 6therein said channel forming a window lil in the sidewall of the casing,In mounting the movable member 6 in the channel it), the movablecontactor 7 and the stopper plate 6 are first passed through thethrough-hole 6a in said movable member after compressing said movablecontactor and said stopper plate with the spring 9 interposedtherebetween, and then, after mounting the movable member 6 in thechannel it), the compressive force is removed, whereby the stopper plate8 is pressed against the inside surface of the casing and the movablecontactor 7 against the fixed contactor 5 under the biasing force of thespring 9. In this case, the end 6b of the movable member 6 extends intothe stepped hole 3 but the other end 60 does not project outwardlythrough the window ll.

Covers 12 to close the respective cavities 4 are fixed to the casing llby means of screws 13 to prevent the movable member 6 and otherswitching members disposed in each cavity 4 from coming off therefrom,whereby a unit switch A is formed. The undersurface of the cover 12 andthe bottom sur' face of the channel are formed with grooves 12a and 10arespectively for receiving projections 6d therein, which projections 6dare formed at the top and bottom surfaces of the movable member 6. Thus,it will be seen that the movable member 6 makes a reciprocatory movementin the cavity, with the projections 6d being guided by the grooves 112aand Mia respectively. Reference numeral I4 designates one of theshoulders defined by the upper projection 6d, which is located closer tothe end 612 of the movable member 6, and a throughhole 12b is formed inthe cover I2 at :a location corresponding to said shoulder M so thatsaid shoulder M is visible from the outside of the cam switch.

Each sidewall of the casing 1 has a portion thereof projected outwardlyas at 115 so as to provide means for connecting the unit cam switch Awith another unit cam switch. Namely, an upright cylindrical portion 15ais formed on the upper surface of the projecting wall portion, while acylindrical cavity I5!) is formed in the undersurface thereof inalignment with said upright cylindrical portion 15a for engagement witha cylindrical portion 15a of another unit cam switch. Between the hollowin the cylindrical portion 15a and the cylindrical cavity 15b is formeda barrier wall 15c. A connecting screw 16 consists of a head 16c, a stemportion 16a and an externally threaded portion 16b formed at the lowerend extremity of said stem portion, said stem portion 160 being slightlysmaller in diameter than the outer diameter of the threaded portion11612. The head 160 of the connecting screw 16 is provided with aninternal thread 116d for engagement with the externally threaded portion16 b of the connecting screw of another unit cam switch. The connectingscrew 116 is inserted from the upright cylindrical portion 15a and screwthreaded through the barrier wall 115C, with the externally threaded endportion 1612 located within the cylindrical cavity iSb. Therefore, thestem portion 116a of the connecting screw 16 extends loosely through thetapped hole 115d formed in the barrier wall as a result of tappingoperation of the externally threaded end portion 16b. Sincetheconnecting screw 16 is mounted in the projecting wall portion 15 of thecasing in the manner described, it cannot be removed from the casingunless it is lifted upwardly while screw threading the same through thetapped hole 15d formed in the barrier wall 15c, and, therefore, saidconnecting screw is disengageably retained by the casing. In connectinga plurality of unit cam switches A with each other in a juxtaposedrelation, the upright cylindrical portion 150 of one unit cam switch isinserted into the corresponding cylindrical cavity 15b of the adjacentunit cam switch and then the externally threaded end portion 16b of theconnecting screw 16 of the former is screw threaded into the internallythreaded hole 16d in the head of the connecting screw 16 of the latter.Therefore, it is not necessary to provide separate connecting means.

A juxtaposed cam switch assembly obtained by connecting a desired numberof unit cam switches A, each constructed as described above and havingthe operating cam 2 mounted in the stepped hole 3, in ajuxtaposedrelation, can be connected to an operating element B in the manner asshown in FIG. 11,

In operation, when the end 6b of the movable member 6 is pushed by therotating cam 32, the movable member 6 is caused to slide outwardly inthe channel it), so that the movable contactor 7 is disengaged from thefixed contactor 5 to open the associated circuit and the end 60 of saidmovable member projects outwardly through the casing ll indicating thestate of the interior circuit. In this case, the spring 9 is compressedwith one end thereof bearing against the stopper plate 6 which issecured in pressure Contact with the inside surface of the casing l, andthereby a force is retained in said spring for the return movement ofthe movable member 6. Then, the pressure is removed from the movablemember 6 upon further rotation of the operating cam 2, whereupon themovable member 6 returns to its original position under the biasingforce of the spring 9, so that the movable contactor 7 is again broughtinto contact with the fixed contactor 5 to close the circuit andaccordingly the and 6c of the movable member 6 is retracted into thewindow ll.

Therefore, when the unit cam switches A are assembled in a juxtaposedrelation as shown in FIG. I, the positions of the respective unit camswitches can be individually readily known from the outside and this ishighly effective and convenient from the standpoint of operationalcontrol. In addition, since the operation of the interior circuit can bedirectly indicated by the movable member 6, a positive operation can beassured and the possibility of erroneous indication can completely beavoided.

It is also to be noted that according to the present invention thecavities 4 in the casing l of each unit switch A are individually closedby the cover 12 when the plurality of the unit switches are assembled ina juxtaposed relation and connected to the operating element B as shownin FIG. 1, so that there is no fear of the movable member 6 and thefixed contactor 5, accommodated in the cavity 4, being slipping ofitherefrom, which facilitates the assembly work. By the same reason, thecomponent parts disposed in each cavity 4 can be maintained in theorderly arrangement even when the unit switch is left to stand singlyand, therefore, handling of the unit switch is very easy.

Moreover, according to the present invention the movable member 6 isformed with the through-hole 6a therein, and the movable contactor 7 andthe stopper plate 8 are supported in said through-hole 6a, with thespring 9 interposed therebetween. in assembling the unit switch,therefore, the operation of mounting these members in each cavity 4 inthe casing 1 can be accomplished in a single step and accordingly theoperation of assembling the unit switch can be much simplified as awhole. Such an arrangement is also advantageous in preventing scatteringand loss of the component parts during assembly, which have beenexperienced in assembling a conventional switch of this type by mountingthe movable member 6, the spring 9, the movable contactor 7, etc. oneafter another individually.

' In the present invention, since each cavity 4 is closed by the cover12, it may be possible depending upon the shape of the operating cam 2that the end 6b of the movable member 6 projecting into the stepped hole3 from the cavity 4 has to be cleared away from said stepped hole toprovide for mounting of the operation cam in said stepped hole. This canbe attained very easily by inserting a small driver or other small tool,readily available to the workmen, into the hole 12b in the cover 12 atits tip end and moving the movable member 6 against the spring 9 bypushing the wall of the shoulder 14 formed on the top surface of saidmovable member. Thus, the operating cam 2 can be mounted in the steppedhole 3 very simply and easily.

The operation of juxtaposing the unit switches A can also beaccomplished simply by means of the connecting screws 16 provided on thecasing l of each unit switch, without requiring any additional fitting.

Although in the embodiment shown use is made of the elongate box-shapedcasing having two switching members accommodating cavities formedtherein, it is to be understood that the present invention is notrestricted only thereto.

What is claimed is:

l. A cam switch unit of the type comprising a casing, an operating cammounted centrally in said casing, a movable member received in each ofcavities formed in said casing on both sides of said operation cam, amovable contactor carried by said movable member and a fixed contactordisposed in each of said cavities for cooperation with said movablecontactor, characterized in that each of said cavities is closed by acover with said respective movable members disposed therein.

2. A cam switch unit of the type comprising a casing, an

operating cam mounted in a hole formed centrally in said casing, and afixed contactor and a movable contactor and a movable member disposed ineach of cavities formed in said casing on both sides of said operationcam, characterized in that said movable member is assembled with saidmovable contactor and a stopper plate by inserting the latter through athrough-hole formed in the former with a spring interposed between saidmovable contactor and said stopper plate, and is slidably fitted in achannel formed across each of said cavities in communication with saidoperating cam mounting hole together with said movable contactor andsaid stopper plate upon compressing said spring, whereby said stopperplate is held in pressure contact with the wall of the cavity, whilesaid movable contactor is held in contact with said fixed contactor inopposed relation thereto.

3. A cam switch unit of the type in which each switching memberaccommodating cavity is closed by a cover, characterized in that amovable member disposed in said cavity and carrying a movable contactoris formed with a shoulder and a through-hole is formed in said cover ata location corresponding to said shoulder.

4. A camswitch unit comprising a casing having switching member 13accommodating cavities formed therein, and operating cam mountedcentrally in said casing, a movable member disposed in each of saidcavities to be operated by said operating cam, a movable contactorcarried by said movable member and a fixed contactor cooperating withsaid movable contactor for effecting a switching operation, said movablemember extending across said cavity with one end thereof confrontingsaid operating cam and the other end projecting into an opening formedin the wall of said casing so as to be visible from the outside.

5. A cam switch assembly comprising a plurality of cam switch units,each of said cam switch units comprising a casing, an operating cammounted centrally in said casing, a movable member received in each ofcavities formed in said casing on both sides of said operating cam, amovable contactor carried by said movable member and a fixed contactordisposed in each said cavities for cooperation with said movablecontactor, each of said cavities being closed by a cover,

connecting means for attaching adjacent of said cam switch unitstogether, said connecting means comprising an upright cylindricalportion formed on the top surface of said casing projecting upwardlytherefrom, a cylindrical cavity formed in the bottom surface of saidcasing for engagement of the upright cylindrical portion of saidadjacent cam switch unit, a barrier wall separating the hollow of saidupright cylindrical portion and said cylindrical cavity,

a connecting screw consisting of a head, a stem portion and anexternally threaded portion formed at the free end of said stem portionand having an outer diameter slightly larger than the diameter of saidstem portion,-said head being provided with an internally threaded holetherein for engagement with the externally threaded stem portion of thecorresponding connecting screw of another cam switch unit and saidconnecting screw being screw threaded through said barrier wall intosaid cylindrical cavity and retained in position with the stem portionthereof extending in the tapped hole formed through said barrier walls,and

common operating means operatively connected to each of said cams foroperating said cams concurrently.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0- 3. 614.363 Dated October 19 1971 Invent0r(S) Teizo Fuiita It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Col. 3, 1. 60, "operation" should read. operating".

C01. 4, 1. 4, 'ope ration should read 'operating".

Col. 4, 1. 23, l3 should be deleted.

Signed and sealed this 1 1 th day of July 1 972.

(SEAL) Attest:

EDWARD M.FLETCHER,JH. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents PC4050 ($69) USCOMM-DC 50376-P69 LLS. GOVERNMENT PRlNTINGU'FICK I959 O 355'33

1. A cam switch unit of the type comprising a casing, an operating cammounted centrally in said casing, a movable member received in each ofcavities formed in said casing on both sides of said operation cam, amovable contactor carried by said movable member and a fixed contactordisposed in each of said cavities for cooperation with said movablecontactor, characterized in that each of said cavities is closed by acover with said respective movable members disposed therein.
 2. A camswitch unit of the type comprising a casing, an operating cam mounted ina hole formed centrally in said casing, and a fixed contactor and amovable contactor and a movable member disposed in each of cavitiesformed in said casing on both sides of said operation cam, characterizedin that said movable member is assembled with said movable contactor anda stopper plate by inserting the latter through a through-hole formed inthe former with a spring interposed between said movable contactor andsaid stopper plate, and is slidably fitted in a channel formed acrosseach of said cavities in communication with said operating cam mountinghole together with said movable contactor and said stopper plate uponcompressing said spring, whereby said stopper plate is held in pressurecontact with the wall of the cavity, while said movable contactor isheld in contact with said fixed contactor in opposed relation thereto.3. A cam switch unit of the type in which each switching memberaccommodating cavity is closed by a cover, characterized in that amovable member disposed in said cavity and carrying a movable contactoris formed with a shoulder and a through-hole is formed in said cover ata location corresponding to said shoulder.
 4. A cam switch unitcomprising a casing having switching member 13 accommodating cavitiesformed therein, and operating cam mounted centrally in said casing, amovable member disposed in each of said cavities to be operated by saidoperating cam, a movable contactor carried by said movable member and afixed contactor cooperating with said movable contactor for effecting aswitching operation, said movable member extending across said cavitywith one end thereof confronting said operating cam and the other endprojecting into an opening formed in the wall of said casing so as to bevisible from the outside.
 5. A cam switch assembly comprising aplurality of cam switch units, each of said cam switch units comprisinga casing, an operating cam mounted centrally in said casing, a movablemember received in each of cavities formed in said casing on both sidesof said operating cam, a movable contactor carried by said movablemember and a fixed contactor disposed in each said cavities forcooperation with said movable contactor, each of said cavities beiNgclosed by a cover, connecting means for attaching adjacent of said camswitch units together, said connecting means comprising an uprightcylindrical portion formed on the top surface of said casing projectingupwardly therefrom, a cylindrical cavity formed in the bottom surface ofsaid casing for engagement of the upright cylindrical portion of saidadjacent cam switch unit, a barrier wall separating the hollow of saidupright cylindrical portion and said cylindrical cavity, a connectingscrew consisting of a head, a stem portion and an externally threadedportion formed at the free end of said stem portion and having an outerdiameter slightly larger than the diameter of said stem portion, saidhead being provided with an internally threaded hole therein forengagement with the externally threaded stem portion of thecorresponding connecting screw of another cam switch unit and saidconnecting screw being screw threaded through said barrier wall intosaid cylindrical cavity and retained in position with the stem portionthereof extending in the tapped hole formed through said barrier walls,and common operating means operatively connected to each of said camsfor operating said cams concurrently.